[Note: To read the full text of this article free click here. Celecoxib (brand name Celebrex) is an NSAID used to relieve pain, tenderness, swelling and stiffness caused by osteoarthritis, rheumatoid arthritis and spinal arthritis. The drug has been linked to added risk of heart attack or stroke; hence the comment that “Serious and cardiovascular adverse events were similar in the two groups.”]

Background: Preclinical studies indicate that the enzyme cyclooxygenase 2 plays an important role in ultraviolet-induced skin cancers. We evaluated the efficacy and safety of celecoxib, a cyclooxygenase 2 inhibitor, as a chemopreventive agent for actinic keratoses, the premalignant precursor of nonmelanoma skin cancers, and for nonmelanoma skin cancers, including cutaneous squamous cell carcinomas (SCCs) and basal cell carcinomas (BCCs).

The primary endpoint was the number of new actinic keratoses at the 9-month visit as a percentage of the number at the time of randomization. In an intent-to-treat analysis, the incidence of actinic keratoses was compared between the two groups using t tests. In exploratory analyses, we evaluated the number of nonmelanoma skin cancers combined and SCCs and BCCs separately per patient at 11 months after randomization using Poisson regression, after adjustment for patient characteristics and time on study. The numbers of adverse events in the two treatment arms were compared using ?2 or Fisher exact tests. All statistical tests were two-sided.

Results:

• There was no difference in the incidence of actinic keratoses between the two groups at 9 months after randomization.

• However, at 11 months after randomization, there were fewer nonmelanoma skin cancers in the celecoxib arm than in the placebo arm (mean cumulative tumor number per patient 0.14 vs 0.35; rate ratio [RR] = .43, 95% confidence interval [CI] = 0.24 to 0.75; P = .003). [Note: an RR of 1.0 would mean no difference. The RR of .43, for example, represents a 57% average reduction in tumor number/risk.]

After adjusting for age, sex, Fitzpatrick skin type, history of actinic keratosis at randomization, nonmelanoma skin cancer history, and patient time on study:

• The number of nonmelanoma skin cancers was lower in the celecoxib arm than in the placebo arm (RR = 0.41, 95% CI = 0.23 to 0.72, P = .002)